Technical Field
The present disclosure generally relates to batteries intended to power electronic circuits and, more particularly, to thin-film lithium ion batteries.
Description of the Related Art
Lithium ion batteries have significantly developed over the last years. Such thin-film batteries, called all-solid (as opposed to liquid electrolyte batteries), may be manufactured by using microelectronics technologies.
Up to now, industrially-available batteries of this type require the deposition of a metal lithium layer, as a negative electrode, between a layer forming the electrolyte and a negative current collector, generally made of copper. The forming of such a metal lithium layer generates significant manufacturing constraints in terms of method, of pollution, and of security. In particular, metal lithium melts at less than 200 degrees, which raises issues for the subsequent manufacturing steps. Further, a lack of control of the thickness of the deposited layer entails risks of battery explosion.
Research has been conducted to avoid the deposition, on manufacturing, of a metal lithium layer. Such batteries, formed with no metal lithium layer deposition on the negative electrode side, are currently not industrially reliable, due to a significant drop in capacity and to a strong increase of the internal resistance of the battery during the successive charge and discharge cycles.